What is Alzheimer's disease?
Alzheimer's disease meaning Alzheimer disease (AD) is one form of dementia, a loss of brain function that occurs with certain diseases. It affects memory, thinking, and behavior. Alzheimer's affects memory, thinking, and behavior. The exact cause of Alzheimer disease (AD) is not known. Research shows that certain changes in the brain lead to AD developing. There are two types of AD:Early onset AD: Symptoms appear before age 60. This type is much less common than late onset. It tends to get worse quickly. Early onset disease can run in families. Several genes have been identified.Late onset AD: This is the most common type. It occurs in people age 60 and older. It may run in some families, but the role of genes is less clear.